Generator



2 SHEETS-SHEET l E. J. DUFFY rGENERATOR Nov. 6, 1951 Filed Deo. lo, 194e INVENTOR. EMMET J. D FFY BY ATTOR EY 2 SHEETS-SHEET 2 E. J. DUFFY GENERATOR Nov. 6, 1951 Filed Dec. 10, 1946 dmv (D aPnHI apnIIldl-UV AIIEEH ONGC @252m s222291 W apnuldmv apnmdmv INVENTOR. EMMET J. DUFFY ATTO RNEY Patented Nov. 6, 1951 GENERATOR Emmet J. Duffy,- Oak Park, Ill., assigner to Hazeltine Research, Incl,` Chicago, Ill., acorporation of Ilflnois Application December 10, 1946, Serial No. 715,327 if Gains., (creto-2.7)

This invention is directed to. arrangements for generating voltages having recurring trace and retrace portions and, particularly, to such.gen erators wherein energy is transferred from ya kfirst energy-storage device to a second energy-store age. device, the charging and discharging of the latter being effective to develop the desired volt,- age. An arrangement of this character has parn ticular utility in connection with av synchroscopc. Accordingly, the invention will be described in that environment.

A synchroscope is an oscilloscope having an adjustable` shortfduration sweep which is pro,- duced only when a synchronizing signal is ap,-` plied to the input electrodes of the sweep generator associated with the horizontal defleeting plates ofthe cathode-ray tube. Such a device is adapted for use in investigating wave forms, measuring various electrical `characteristics such asvoltage, current, and phase angle, comparing from their lower recurrence rate values so tl'latl for some purposes, information of suicient accuracy is not obtainable. This decrease in the duration and the maximum amplitude of the sweep potential is principally due to the fact thatY an energy-storage device or condenser in the sweep generator circuit does not, after one or more cycles of operation at a higher repetition rate, charge to a sumciently high potential level prior to its partial discharge during the succeeding cy, cle ofoperation. Accordingly, the trace portions of sweep potentials developed at the' higher repetition rates are shorter than the corresponding trace portions developed at the lower repetition rates. Consequently measurements or observations under some conditions may be inaccurate and hence not suiciently reliable for those applications requiring a high degree of accuracy.

To avoid some of the foregoing disadvantages,

it has been proposed that the condenser in the sweep generator circuit, which is alternately charged and discharged to produce the desired sweep potential, be chargedfrom a second condenser. ,In the Course of their operatiomhowfever, arrangements of this. character exhibited the same type of disadvantages referred to above.

It is an object of the invention, therefore, to provide a new and improved arrangement for generating a voltage having recurring trace and retrace portions which avoids one or more of the above-mentioned disadvantages andv limitations of priorv such arrangements.

It is another object of the invention to, provide.

a new and improved arrangement for generate ing a voltage having recurring trace and retrace portions wherein the trace portions have` sub-` stantially identical characteristics regardlessofy relatively large variations in the recurrence rate thereof.

It is a further object of the invention to pro-i vide an arrangement for generating a voltage having recurring Y trace, and retrace portions wherein the maximum amplitude of the genei'fA ated voltage is substantially constant inrspite of substantial variations in the recurrence rate 0ry the duration of the trace portions.

It is an additional objectof the invention to provide anew and improved arrangement for use in a Vsynchroscope for generating sweepvoltages having recurring trace and retrace portions,V

In accordance with the invention, an arrange-.- ment for generating a voltage having recurring trace and retrace portions lcomprises a iirst enT ergy-storage means and means including an im-`V pedance means for charging the first energy,-r

storage means at least during spaced recurring intervals. The arrangement also includes ,a'secs ond energy-storage means and means including the above-mentioned impedance means for charging the second energy-storage means during spaced recurring intervals intermediate thevv vention, together with other and further, objects thereof, reference is had to the following description taken in connection with the accorti:`

panying drawings, and its scope will be pointed out in the appended claims.

Referring now to the drawings, Fig. 1 is a circuit diagram, partly schematic, of a synchroscope including a voltage generator embodying the present invention in a preferred form; Figs. 2a and 2b comprise graphs of voltages developed in the voltage generator of Fig. 1 under diierent operating conditions.

Referring now more particularly to Fig. 1 o the drawings, the synchroscope there represented comprises a vertical deflection ampliiier I Il including a pair of input terminals II, II and an output circuit which is coupled to the vertical deiiecting plates of a conventional cathode-ray type image-reproducing device I2. A voltage generator I3 for producing sweep potentials for the image-reproducing device I2 has a pair of input terminals I4, I4 and an output circuit including terminals I5, I5 which are coupled through coupling condensers I6 and I1, respectively, to one of the horizontal deilecting plates of the image-reproducing device I2 and to the input circuit of a phase inverter I8. The generator I3, which is constructed in accordance with the present invention, is shown in detail and will be described fully hereinafter. The output circuit of the phase inverter I8 is coupled to the other horizontal deflecting plate of the image-reproducing device I2.

The synchroscope of Fig. 1 as thus far described is, in general, well understood in the art so that a detailed explanation of its operation is deemed unnecessary. Briefly, however, the application of a synchronizing signal to the input terminals I4, I4 of the generator I3 causes the latter to develop at the output terminals I5l I5 a sweep potential having trace and retrace portions like those of a saw-tooth wave. This sweep potential is applied through the condenser I6 directly to one of the horizontal deflecting plates of the image-reproducing device I2 and is also applied through coupling condenser I'I to the phase inverter I8 where it is reversed in polarity. The output signal of the phase inverter I8 is applied to the other deflecting plate of the irnage-reproducing device I2, thus providing balanced sweep potentials for the pair of horizontal defiecting plates. These sweep potentials deect the electron beam of the image-reproducing device I2 horizontally from left to right at a uniform rate across the fluorescent screen during the trace portions of the sweep potentials. A phenomenon under investigation, for example, the wave form of an unknown signal, is applied to the vertical signal-input terminals II, I I during the trace period and is amplied in unit I0. The output signal of the latter is applied to the vertical deflecting plates of the image-reproducing device I2 and is effective to deflect the electron beam vertically of the screen so that there is reproduced thereon the wave form of the phenomenon which is being studied. During the retrace interval the electron beam is returned to its original position at the left of the screen of the image-reproducing device I2, and preferably is suppressed during the retrace period in the well-known manner. After an interval of time another synchronizing signal may be applied to the terminals I4, I4 and the same or a second signal to be investigated is applied to the terminals II, II of the vertical deilection amplifier I0 during the trace portions of the balanced sweep signals which are impressed on the horizontal deiiecting plates of the image-reproducing device I2. The pattern of the second signal under observation is similarly traced by the electron beam before the latter returns to its original position at the left of the iluorescent screen.

Referring now more particularly to the portion of .the synchroscope of Fig. l which embodies the present invention, the voltage generator I3 for developing a voltage having recurring trace and retrace portions comprises a rst energy-storage means in the form of a condenser having a relatively large capacitance. The generator also comprises means including an impedance means for charging the condenser 20 to a predetermined voltage level across its terminals. This charging circuit comprises a source of unidirectional potential +B which is connected to one terminal of the condenser 20 through a diode 2| and to the other terminal of the condenser through the aforesaid impedance means which comprises a. resistor 23 having a relatively large value. The resistor 23 comprises the cathode or output resistor for a cathode-follower repeater means which includes a pentode electron tube 25. The anode of the pentode 25 is connected directly to the source +B while the screen electrode is connected thereto through a voltage-dropping resistor 26, the low-potential terminal of which is connected to the cathode through a by-pass condenser 21. The suppressor electrode is connected directly to the cathode of the pentode.

The voltage generator I3 also includes a second energy-storage means in the form of a selectable one of a plurality of condensers 29, 29', and 23, each of which has a capacitance relatively small with respect to that of condenser 23. The capacitances of the condensers 29, 29', and 29 are progressively larger in the order named. The generator arrangement additionally comprises means for charging any of the condensers 23, 29', or 29" with energy supplied by the ilrst condenser 20 to develop the trace portions of the voltage. This charging circuit includes a relatively large adjustable resistor 30, preferably having a value which is larger than that of the resistor 23, which is connected between the cathode of the diode 2I and a switch arm 3I which is adjustable for selective engagement with any of the ungrounded terminals of the last-mentioned condensers. The cathode resistor 23 is also in the last-described charging circuit since it is effective partially to determine the eiective output impedance of the cathode-follower repeater 25, which constitutes a portion of this charging circuit as will be made clear subsequently. The switch arm 3I is connected to the control electrode of the pentode 25 through a resistor 4I, and the high-potential terminal of the resistor 23 is connected to one of the output terminals I5.

The generator arrangement of the present invention further includes an electron-discharge means or pentode 33 which is adapted alternately to have one conductive condition and then another conductive condition. As will be made clear hereinafter, pentode 33 is effective during the aforesaid one conductive condition to discharge a desired one of the condensers 29, 29 or 29" to develop the retrace portion of the sweep voltage. The anode of the pentode 33 is connected to the low-potential end of the resistor 30 while the cathode and suppressor electrodes are connected directly to ground. The screen electrode is connected to the source +B through a voltage-dropping resistor 34 and is by-passed to ground through a condenser 35. One input terminal I4 for the synchronizing signals is conagognata.:

includes a grid-leak resistor 38.

The sweep generator additionally includesa device .inthe-.form of ay switching devicerhaving a valueof impedance which.maybezvariedfor reducing the effective impedance value. ofthe cathode resistor 23 during the retrace portions. of. the generator voltage. This device comprisesV atriode 40 having output terminals effectively connected in shunt .with they resistor'23 for reduc+l ing the .effective value of the .resistor 23 or,A more particularly, the effective. output .impedance of the cathode-follower repeater 25. The anode ofi thettrioded is connected to the cathodeoftube.

25 and thecathode ,isagrounded The-f control electrodeof the triode is connectedtoxtheun grounded input-terminal I4.

Considering now the operation ofthe described generator with reference to the graphs of Fig. 2a but neglecting for the moment the function ofl the triode 40, it will be assumed initially that at time topentodes 25 and 33 are conductive and thatthe condenser is charged to a predetermined. voltage between its terminals which is slightly below that of the source +B, as shown in curve B of the above-mentioned figure. During. time tf1-t1, the potential ofthe cathode of tube is slightly higher than that of the control electrode thereof as represented, respectively, by the broken-line curve C and the fullline curve. D. This potential difference is not sufficiently large to prevent the conduction of space current through the tube 25. It will also be assumed that at t1 a first synchronizingsignal of the type illustrated in curve A ofFig. 2a is applied to the input terminals I4, I4 with negative polarity with respect tothe control electrode higher repetition rate than thatwhich provides.

a wholly reliable operation.

Theapplication of the .synchronizing signal' at time t1 alters the status of tube 33 from one con-V ductance condition to a different conductance condition by biasing the tube beyond cutoff for the duration tr-tz of the signal, thus opening the anode-cathode discharge path for the confdenser 29. In response to this different operating condition of the tube 33, condenser 29 thereupon begins to charge from the condenser 20. through the resistor 39 and the resistor 23./the latter' being an element in a parallel impedancev combination which includes the alternating-cur.'-

rent anode-cathode impedance of the cathode#- follower tube 25. Since tube 25 is conductive during the interval t1-t2, the impedance presented.

by the resistor 23 and the space-current path of tube 25 is the eifective output impedance of` Condenser 29.l

the cathode-'follower repeater. chargeslinearly in the mannerrepresented by the curve D of Fig. 2a. As the ungrounded terminal of condenser 29 rises in potentiallevel, thisv increase is applied to the control electrode of.

tube 25 through the resistor 4|. Since tube. 25 is operating as a .cathode follower, a similar potential increase appears'at thefcathode: thereof and, hence, at the output-..terminalzIii-which ist.

. 33. thereby developing the retrace portion of the,v

. 6 directly connected thereto". The cathode potential and the" control-electrode potential tend .to apfproach each other gradually'during the interval iti-t2 as illustrated in the curves C and D. Hence the control electrode and the cathode of tube 25 increase in potential at almost identical rates and.. since thepotential across the terminals-of condenser 20 remains nearly constant during the foregoing interval, the current flow` through. thev resistor. 30 and hence the charging current for the'condenser 29 has a substantially constant value.

the output terminals I5, I5.

During the interval tr-tz, the level. of theflowpotential electrode of the vcondenser 20V increasesv in the'. manner represented by the broken-line curve C since that electrode is connected directly to' the cathode vof the tube 25. SimultaneouslyY therewith the high-potential electrode of the condenser 20, which is connected to the cathode of the diode 2|, rises in potential from the level m, which issomewhat less than +B, to the level n which is above the +B level as shown in curve B, thus holding thediode 2l beyond cutoff. It

will be observed from the slope of curves B and C during the interval ti-tz that the high-potential electrode rises at a lower rate than the low-potential electrode due to the charge which.

isbeing accumulated by the condenser 29.

The synchronizing signal terminates at. time t2 .and,.sincevthe pentode 33. is then operating without a bias, it becomes conductive, thus returning. to the aforesaid one conductive condition. Condenser 29 thereupon discharges quickly.y

and somewhat linearly through a circuit having a relatively short time constant, which circuit includes the space-current path of the pentode sweep voltage. This discharge of the condenser 29 during the interval tz-ts, as it affects the control electrode of the cathode follower 25, is represented by the curve D of Fig. 2a. The cathode potential of tube 25, however, decreases at a somewhat lower rate than that of the control electrode thereof during the interval 152-453. Ac-

cordingly the cathode potential becomes sufii` ciently higher than that of the control electrode that tube 25 is biased beyond cutoff at about time t3. Also duringthe interval tg-ta the highpotential termina-l of the condenser 23 .falls from the level n to the level o which .is below that of ythe source +B, as illustrated in curve B of Fig. 2a. Since the cathode of the diode 2i is now below the +B level at time t3the diode becomes conductive and the condenser 29 charges slowly as indicated in curveB until the potential across. the terminals thereof again reaches the level m at approximately time t5.

It will be observed from curves C and D that,

during the interval ita-t5, the cathode potential.

of tube 25 remainsconsiderably higher thanthat of the control electrode thereof. Accordingly,

the pentode 25 is biased beyond cutoff during the.

25,the impedance between the cathodev of tubev 251and ground has a high value. This is effective .materially to reduce the charging rate of the condenser20 and prevents it from being charged. tojits proper level m prior to the application .ofi

asecondsynchronizing signal.

Thus, the condenser 29 charges linearlyl anda vsimilar output voltage is applied across At time t5 a second synchronizing signal is ap, plied to the input terminals I4,v I4 of the gener-A ator I3` This signal biases the pentode 33 beyond cutoi and the condenser 20 begins to charge the condenser 29 through the resistors 30 and 23. During the interval ts-ts the potential level of the cathode of the pentode 25 is still considerably higher than that of the control electrode thereof so that the tube is still in a nonconducting state. As the condenser 29 is being charged during the last-mentioned interval, the potential of the control electrode of tube 25 increases and approaches that of the cathode thereof. At time ts the potential difference between the control electrode and the ca-thode reaches the critical value whereupon the tube 25 becomes conductive. The increase in potential across the input terminals' of tube 25 is then translated across the resistor 23 and the output terminals I5, I5 by cathode-follower action so that the second traceV portion of the output Voltage appears during the interval ts-tv as represented by th-e broken-line curve C of Fig. 2a. The synchronizing signal terminates at time t7, thus ending the trace portion and initiating the retrace portionv in the manner previously explained. The control-electrode potential returns to its original value at time ta while the cathode potential decreases slowly in the manner previously ,mentioned in connection with the corresponding preceding intervals.

It will be observed that the second sweep potential of curve C has a foreshor-tened trace portion. It will therefore be apparent that a recurrent sweep signal of this character, when utilized in connection with a synchroscope or similar device, may result in the production of a very inaccurate display of information on the screen of the image-reproducing device I2. For example, information which should be displayed during the intervals ts-ts will be completely absent.

Considering now the operation of the voltage generator I3 as influenced by the action of the triode 40, with reference to the graph of Fig. 2b, it will again be assumed that at `time t1 the condenser 20 has been fully charged to the level m and that tubes 25, 33, and 40 are all conductive. While the cathode of tube 25 is somewhat more positive than the control electrode thereof, it is not sulliciently positive to prevent the flow of space current. At time t1 the negative synchronizing signal of curve A is applied to the input terminals I4, I4 and it biases tubes 33 and 4i) beyond cutoff so that the condenser 20 begins to charge the condenser 29 through the resistor 30 and the eiective output impedance of the cathode follower including the tube 25. While the condenser 29 increases in potential, the control electrode of tube 25 rises in potential during the interval ti--tz as illustrated in curve D'. The cathode of tube 25 increases linearly in potential as illustrated in curve C' of Fig. 2b for reasons which were previously explained in detail in connection with Fig. 2a. During the interval t1-t2 the potential across the terminals of condenser 20 increases from the level m' to the level n as represented in curve B of Fig. 2b.

At time t2 the synchronizing signal terminates and the tubes 33 and 40 again return to their normally conductive state. This permits the condenser 29 to discharge through the anode-cathode of tube 33, thus causing the control-electrode potential of tube 25 to decrease abruptly during the interval ta-ta as illustrated in curve D'. The cathode potential and that of the highfpotential electrode of the condenser 20 also decrease steadily although at a somewhat slower rate during,

the interval tz-ts as represented by the curves C' and B', respectively. The high-potential electrode of condenser 20 falls to a level o which is below the +B level and also the level m at which the condenser is fully charged. Consequently the diode 2| becomes conductive at approximately time tavand the condenser begins to charge from the source +B. At time ts the cathode potential of tube 25 exceeds the control-electrode potential thereof by the critical value so that the tube is biased beyond cutoi. This would normally increase the cathode-to-ground impedance to a large value corresponding to that of the resistor 23 but for the action of the triode 40 which is now in a conductive state, as mentioned above.

Accordingly the parallel combination of the triode 40 and the resistor 23 is eiective to provide a low cathode-to-ground impedance at the cathode of tube 25 during the interval ta-ts so that the potential at the aforementioned cathode quickly falls to its initial level at time t4 While the condenser 20 is charged to its initial level m' at approximately time t4. Diode 2| then becomes nonconductive. Resistor 30, due to its relatively high value of impedance, effectively isolates the condenser 20 from the discharge path for the condenser 29 through the tube 33.

During the interval tl-ts the voltage generator I3 is in the same operating condition it was in during the interval 1ro-t1.v Hence, at any time during the period t4-t5 the generator I3 is in a position to respond to a second synchronizing signal. Consequently, when a second synchronizing signal is applied to the input terminals I4, I4 at time ts, the above-described cycle of operation is repeated, thereby producing a sweep voltage having a trace portion during the interval ts--t'z Iwhich corresponds in duration and amplitude with the trace portion of the preceding sweep voltage at time t1--t2. Likewise the retrace portion during the period t1t9 is of a short duration which is equal to that of the preceding retrace interval tz-tl.

Thus the generator I3 including the triode 40 is effective at the higher repetition rates to produce sweep voltages .wherein the individual sweeps correspond in amplitude and in duration. This is most important in connection with the accurate displaying of information which may have occurred at any instant during the trace interval. It has been determined experimentally with prior arrangements which were operated at the higher repetition rates that as much as twenty to tWenty-iive per cent of the trace portions of the sweep potentials were unobtainable and that the sweep durations also fell in substantially the same percentage. Accordingly, the trace portions of the sweep potentials developed by the generator I3 in accordance with the instant invention do not have ineffectual regions such as that during the interval ts-te which is illustrated in Fig. 2a of the drawings.

It will be manifest that operation similar to that described in connection with Fig. 2b will result when the sweep duration is increased, as by operating the switch arm 3I to make engagement with either of the larger condensers 29 or 29' Hence, it is unnecessary to repeat the above explanation.

While applicant does not wish the invention to be limited to any particular structural arrangement. the following more important values are given byway of example. A l i 9 Resistor 23, 33,000 ohms --;Resistor30, .1A-18,000 ohms (maximum) :'Resistor Il l., 100 vohms `CondenserrZlL 0.01 miorofarad Condenser 29,35 micromicrofarads Condenser v300.micrcmicrofarads Condenser 29, 0,001'75 microfarad Tubes and `3 3i, type 6SJ '7 Tube 40, type 6SN7 +B, 400 volts ySweep voltage amplitude, 220 volts Sweep voltage recurrence rate, 200 to 4700-cyc1es per second .A Duration of one period of sweep:

V(1) 5 microseconds (approx.)

(2), 20 microseconds (approx.) (3), 100 microseconds (approx) It will be apparent from the above" description "and explanation of the operation of one form of 'the invention, that the voltage generator of the instant invention is adapted to provide, for any particular sweep duration setting ofthe generator, individual sweep voltages having substan- 'tially identical characteristics despite relatively wide variations in the repetition frequency.

While there has been described whatv is at present considered to be the preferred embodiment of this invention, it will be obvious .to 4.those skilled in the art that various Vchanges and 'modications may be made therein without de- ,parting from the invention, and it is, therefore, vairned'in the appended Aclaims to cover all such 'changes and modications as fallwithin thetrue "I spirit and scope of the invention.

lWhat is-claimed is:

1. An arrangement 'for` generating a voltage having recurring trace and retrace portions comprising, a rst energy-storage means,..means including an. impedance means for charging 'said first energy-storage means at least during` v4spaced recurring` intervals,a second energyfstoragemeans, means including-said impedance 4means forY charging said second energy-storage means during spaced recurring `intervals intermediate said rst-mentioned intervals with ener- V.gysuppliedby-said rst energy-storage means to develop said trace portions of said voltage, means for discharging said second energy-storage means during said first-mentioned intervals and a device coupled to the vimpedance means .andhaving a Value of impedance which.may,be varied during the nErst-mentioned intervals. to reduce the effective impedance value of, .said impedance meanswduring said retrace portions of said Voltage.

2. An arrangement for generating a voltage having recurring trace and retrace portions comprising, a rst energy-storage means, means including an impedance means for charging said` iirst energy-storagemeans at least during spaced recurring intervals, a small energy-storage means having a storage value small relative i to that of said first energy-storage means, means VVincluding saidV impedance means for charging:

' 10 :.fvaried: duringrfsaid .zrstementioneds intervals to freduce the: effective impedance value ofwsaid impedance means Iduring said retracetportions of 1 said voltage.

5 3. 1in-"arrangementv for generating a voltage 'shaving recurring'trace and` retrace portions comprising: a first-condenser; means including an i: impedancev means for charging said iirst kcon- .Ldenserto a predetermined voltagelevel at least luduring spaced :recurring intervals; a second a condenser; means including said Aimpedance means for charging said second condenser durv"ing" spaced recurring intervals intermediate said rstz-'rnentionedintervals' with energy supplied `by-'said nrst condenser `to develop said trace por- ;'tions'of said :voltage which Vcharging tends to reducethe voltage level across said rst condensf er'belcwisaid'predetermined level; means'for disvcharging saidsecond condenser during said firstmention'ed intervals to develop 'said retrace por- 'r tions of'said voltage; and an electron tubeicoupled *in shunt* with 'said impedance meansand hav- Y ingav value ofaimpedance which is variedduring said first-mentioned intervals to reduce the 25 effective impedance value of saidY impedance means during said retrace portions of `said'voltage so' that the voltage levelvacrosssrsaid first "condenser: is' restoredv substantiallv. Yto said predetermined flevel `during'said retrace portions of'said voltage.

4. An arrangement for generating a voltage having' recurring trace .and fretrace'. portions comprising, arst yenergy-storage `means, 'means Vincludingl an i'iimpedance -means for v'charging 'said nrst energy-'storage means; a second yenergystorage means; an?` electron tubefmeansfincluding the parallel combination of the alternatingcurrent conductive anode-cathode impedance Vof said electron tube and said mpedancemeans 40 for' charging' said second energy-storage vmeans with energy supplied by said rst energy-storage means to develop said trace portions of said voltage; `means for. discharging said secondenergy-storage meansto' develop'said retrace. porftions' 'ofiI said voltage, and a deviceV having a value of impedance which is varied to reduce 'the leffective impedancevalue of said impedance means duringV said` retrace portions of said voltage.

toV develop said retrace portions of said voltage; 5- AT1' rrangement'for 'generatingv a voltage have recurring trace and retrace portions comprising, a'first energy-storage means, an elec- 'trontube, means including a cathode impedance meansfor said electron tubefor charging said rst energy-storage means, a `second energy- 160 Vplied by said 4first energy-storage means to de- `velop said -trace portions of said voltage, meansfor discharging said second energy-storage meansrtodevelop said retrace portions of said vrvoltage,fand a device having a value of fimpedance Whichis varied to reduce the effective impedan'ce value of said cathode impedance means 'f 'and-said space-current path during said 'retrace portions of said voltage.

6. An arrangement for generating a voltage having recurring trace and retrace portions comprising, a rst energy-storage means, means including an impedance means for charging said irst energy-storage means, a second energystorage means, electron-tube repeating means having an input circuit connected across said second energy-storage means and including said impedance means in the cathode circuit of said repeating means for charging said second energy-storage means with energy supplied by said iirst energy-storage means to develop said trace portions of said voltage, means for discharging said second energy-storage means to develop said retrace portions of said voltage. and a device having a value of impedance which is varied to reduce the effective impedance value of v said impedance means during said retrace portions of said voltage.

7. An arrangement for generating a voltage having recurring trace and retrace portions comprising, a first energy-storage means, a cathodefollower impedance means, means including said impedance means for charging said first energystorage means, a second energy-storage means, means including the effective output impedance of said impedance means for charging said second energy-storage means linearly with energy supplied by said rst energy-storage means to develop said trace portions of said voltage, switching means for discharging said second energy-storage means to develop said retrace portions of said voltage, and a device connected in shunt relation with said impedance and having a value of impedance which is effective to reduce the effective output impedance of said impedance means during said retrace portions of said voltage.

'8. An arrangement for generating a voltage having recurring trace and retrace portions comprising, a first energy-storage means, electrondischarge means, means including an impedance means and responsive to one conductance condition of said electron-discharge means for charging said first energy-storage means, a second energy-storage means, means including said impedance means and responsive to a different conductance condition of said electron-discharge means for charging said second energy-storage means with energy supplied by said rst energystorage means to develop said trace portions of said voltage, said electron-discharge means being effective during said one conductance condition thereof to discharge said second energystorage means to develop said retrace portions of said voltage, and a device having a value of impedance which is varied to reduce the effective impedance of said impedance means during said one conductance condition of said electron-discharge means to accelerate the charging of said first energy-storage means during s aid retrace portions of said voltage.

9. An arrangement for generating a voltage having recurring ktrace and retrace portions comprising, a first energy-storage means, electron-discharge means normally having one conductance condition and having a different conductance condition in response to a control effect applied thereto, means including an impedance means responsive to said one conductance condition of said electron-discharge means for charging said first energy-storage means, a second energy-storage means, means including said impedance means responsive to said different conductance condition of said electron-discharge means for charging said second energy-storage means with energy supplied by said first energy-storage means to develop said trace portions of said voltage, said electron-discharge means being effective during said one conductance condition thereof to discharge said second energy-storage means to develop said retrace portions of said voltage, and a device having a value of impedance which may be varied and responsive to said control effect and rendered inoperative thereby during said trace portions of said voltage but normally operative during said retrace portions of said voltage for reducing the effective impedance of said impedance means to accelerate the discharging of said first energystorage means during said retrace portions of said voltage.

10. An arrangement for generating a voltage having recurring trace and retrace portions comprising, a relatively large energy-storage means,y electron-discharge means normally having one conductance condition, means in the space-current path of said electron-discharge means and responsive to a control effect for imparting to said electron-discharge means a different conductance condition, cathode-follower repeating means, means including cathode impedance means for said repeating means and responsive to said one conductance condition of said electron-discharge means for charging said relatively large energy-storage means, a relatively small energy-storage means, means including the effective output impedance of said repeating means and responsive tosaid different conductance condition of said electron-discharge means for charging said relatively small energy-storage means with energy supplied by said relatively large energy-storage means to develop said trace portions of said voltage, said electrondischarge means being effective during said one conductance condition thereof to discharge said relatively small energy-storage means to develop said retrace portions of said voltage. and a triode electron tube in shunt relation with said cathodev impedance means and responsive to said control effect and rendered inoperative thereby during said trace portions of said voltage but normally operative during said retrace portions of said voltage for reducing the effective output impedance of said repeating means during said retrace portions of said voltage to accelerate the charging of said relatively large energystorage means during said retrace portions of said voltage.

EMMET J. DUFFY.

REFERENCES CITED The following references are of record in the le of this Ipatent:

UNITED STATES PATENTS Number Name Date 2,113,011 White Apr. 5, 1938 2,426,256 Zenor Aug. 26, 1947 2,436,890 Higinbotham Mar. 2, 1948 

